How to troubleshoot a Bosch tankless water heater?

Check the wire connections on the gas valve and control board. Measure the voltage on the wires when a water heater is ON… it should be 24 VDC. If the measurement is as specified, the gas valve is malfunctioning. And what do you think about Bosch? Click below to see contributions from other visitors to this page… Had a Bosch heater for 15 years.

What do I need to know about my Bosch water heater?

The primary fan spins slowly when the water heater is working. Check the wiring connection on the fan and control board. The voltage must be 120 VAC and the element correctly grounded. Does the venting system meet the code and manufacturer requirements?

Which is the only company to offer a tankless water heater?

Bosch is the only major tankless water heater manufacturer to offer a built-in digital control panel with the ability to adjust water output temperatures in precise 2°F increments across the entire temperature range, an important safety feature for homes with children and elderly family members.

Can a tankless water heater lose hot water?

A lot of different tankless water heater problems could cause you to lose hot water completely. For starters, regardless of whether you have a gas or electric tankless unit, it could very well just be that you’re pushing the unit to its limits.

Are there any problems with my Bosch tankless water heater?

If you are the owner of a “smart” tankless water heater from Rinnai, Noritz, Paloma, Bosch, Takagi or similar, this troubleshooting guide is for you. The guide deals with the most common problems and explains some of the error codes.

What to do if your tankless water heater has no hot water?

No hot water is one of the most common tankless water heater problems. The first things you should check are the electric power, water, and gas supply to the water heater. Check the shut-off valves, as they might be in the closed position.

Why does my Bosch water heater not make sparks?

The ionization electrodes are not making sparks when water is flowing. There are many reasons for this problem and here are some; low gas pressure, the fan speed is low, wire connections are loose, the air in the gas line, no gas. Ionization electrode failure during water heating.

Why is my Bosch water heater flashing an error code?

This is not an error code; it is a flashing status message that tells you to check; the wiring connection, gas pressure as it might be too low, voltage as it doesn’t meet the required 120 VAC, the unit that might not be properly grounded or the issue with the control board. The primary fan spins slowly when the water heater is working.

What should resistance be for Bosch tankless heat exchanger?

It is important to check for any gas leakage close to the gas combustion chamber and heat exchanger. Check if the limiter is operating and wiring is correctly linked to the control board and limiter. The element is located at the top-right corner of the unit. Measure the resistance on the wire harness; it must be between 115 and 120 ohms.

What does an error code on a Bosch water heater mean?

Get FREE Estimates! Error codes are the indicators of the problems inside the water heater. When the error code appears on the Bosch heater’s LCD display, the reset button sometimes leads to an error removal, but if it doesn’t work, the instructions below might help troubleshoot the problem:

Which is the most efficient Bosch water heater?

Gas tankless and electric water heaters from Bosch. Enjoy peace of mind and savings with highly-efficient and versatile water heaters from Bosch. Our vision is to provide comfort and peace of mind to our customers with compelling solutions created by passionate people. Do you have any questions or suggestions for improvement?

How does a Bosch tankless hot water heater work?

Bosch tankless water heaters work “on-demand” to produce hot water when needed, for as long as needed. There is no storage tank, so you never have to worry about running out of hot water or waiting for the tank to recover, even during peak use. A tank style hot water heater keeps water hot 24 hours a day, whether it is needed or not.

What does temperature sensor mean on Bosch tankless?

The outlet temperature sensor reacts when the temperature is either below 36 F when the unit is protected from freezing temperatures, or above 210 F in a case of overheating due to the lime-scale deposits. Check the sensor and wiring. You might have to flush the unit to remove the mineral build-up.

Where can I get replacement parts for my Bosch gas heater?

GlobalTowne sells replacement parts for all Bosch gas, propane and electric tankless water heaters and electric mini-tanks. We list the most common Bosch heat exchangers, water valves, gas valves, control boards, control boxes and hydrogenerator on this page. Call us at 888.726.9752 for pricing and availability on all other Bosch parts.

How does the Bosch 125b-ng tankless water heater work?

Cut water-heating costs by up to 50 percent with the Bosch AquaStar 125B-NG tankless water heater. The 125B-NG is fueled by natural gas and heats water on demand, supplying hot water at a rate of 4.3 gallons per minute–enough to meet the needs of one major application (shower, dishwasher, etc.) at a time.

What should water pressure be on Bosch tankless?

The voltage needs to be 120 VAC and adequately grounded. Ensure that a fan and control unit are not damaged. Make sure that the water pressure is less than 150 PSI and a flow rate below 10 GPM. Check the wire connections on the water valve and control panel.

What kind of gas does the Bosch 125b-ng use?

The 125B-NG is fueled by natural gas and heats water on demand, supplying hot water at a rate of 4.3 gallons per minute–enough to meet the needs of one major application (shower, dishwasher, etc.) at a time. The 125B-NG uses a standing pilot for ignition.

Can a licensed plumber install a flashshield system?

FlashShield is to be installed only by a licensed plumber/HVAC installer that has successfully completed the Gastite/FlashShield certification test. By checking this box I am acknowledging that I have successfully completed the Gastite/FlashShield certification and I hold a valid Gastite/FlashShield certification card.

SOLUTION: Make sure that the power knob is turned to the highest flame setting and that the temperature knob is adjusted accordingly. Check for blockages on any outlets that are external to the hot water heater. Make sure the water valve is clean so that it will properly open the gas valve.

How to check water pressure on Bosch water heater?

Check that the water pressure of the unit is above 30 PSI, if it’s not you can do the following test to check the flow rate: 1. Shut off the cold water supply and disconnect the hot water supply. 2. Open the cold water supply and put a container underneath to check the water. 3.

What to do if your Bosch water heater is turning yellow?

SOLUTION: Make sure the pilot flame is the right color, if it is yellow please refer to the “yellow flame” section. Make sure the flame sensor is clean and operating properly. Check to see if all the water flow connections are running smoothly without obstructions.

Why does my Bosch Water Heater get Too Hot?

Try increasing the rate of water flow, make sure that all external outlets such as faucets are clean and have no blockages and that the inlet filter is clean. High mineral deposit rate inside the water connections can cause the water temperature to boil and become too hot. If this is the probem it is recommended that you call a professional.

Where is the resistance on a Bosch tankless?

The element is located at the top-right corner of the unit. Measure the resistance on the wire harness; it must be between 115 and 120 ohms. Check the backflow temperature sensor connection; it might be damaged, or it got short-circuited.